Retain injected client diagnostic evidence

llm_adapter.go

@@ -18,16 +18,17 @@ func (a publicLLMClientAdapter) Generate(ctx context.Context, req domain.Generat
 	if err == nil && resp == nil {
 		err = fmt.Errorf("%w: %w: llm client returned nil response", ErrLLMGenerate, ErrMalformedResponse)
 	}
+	response := toDomainGenerateResponse(resp)
 	if err != nil {
 		switch {
 		case errors.Is(err, ErrTransport):
-			return nil, classifiedClientError{cause: err, category: llm.ErrTransport}
+			return response, classifiedClientError{cause: err, category: llm.ErrTransport}
 		case errors.Is(err, ErrMalformedResponse):
-			return nil, classifiedClientError{cause: err, category: llm.ErrMalformedResponse}
+			return response, classifiedClientError{cause: err, category: llm.ErrMalformedResponse}
 		}
-		return nil, err
+		return response, err
 	}
-	return toDomainGenerateResponse(resp), nil
+	return response, nil
 }
 
 // classifiedClientError makes an explicit public category available internally